アメリカ手話 (ASL) from http://www.signingsavvy.com
Rice: finger spell "r" and move you hand like you are picking up rice from a bowl.
Soup - Soup is in the Signing Time Series 1 Vol. 12 "Time To Eat" DVD
With two fingers as the spoon, scoop up the soup from a bowl.
Tea - The sign I use...
One hand makes a cup shape, the other pretends you are holding a tea bag - move your hands like you are swishing a tea bag in your cup
http://shikaku.in/sign/L/search/美味しい/ (cake, yummy)
Pat your cheek to show how yummy the food is!
move your hands like you are making a ball of rice
紅茶 <-- close to the ASL sign)
I've seen 抹茶 signed (by deaf friends) as lifting a green tea tea cup - the same as on the pamphlet.
Check out the Kotoba & Sign Amazon Store for suggestions of books and toys to keep the learning going!
One more link... the Deaf Japan website. It has some interesting things on it! http://deafjapan.com